1. Field of the Invention
This invention relates to a strip decoiler which automatically sets the speed of decoiling so that it smoothly decoils strip material. The decoiler of the invention also carefully transports the strip toward the end use without local stress which might otherwise deform the strip and spoil it.
The decoiler of the invention also has means rapidly and easily to convert the decoiling operation from a clockwise to a counterclockwise take-off, or vice versa, depending on the direction of the coil winding, and still provides a smooth decoiling and transporting operation.
2. Description of the Related Art Including Information Disclosed Under .sctn..sctn.1.97-1.99
The prior art includes many decoiling apparatuses. Decoilers generally of the same type, including a horizontal-driven platform and a take-off arm which controls the speed of the platform, are disclosed in U.S. Pat. No. 3,476,330, which issued Nov. 4, 1969 to Curtland; U.S. Pat. Nos. 4,304,370, which issued Dec. 8, 1981, and 4,610,408, which issued Sept. 9, 1986, both to William A. Box et al.; and U.S. Pat. No. 4,582,271, which issued Apr. 15, 1986 to Takahashi.
Illustratively the Box U.S. Pat. No. 4,304,370 discloses a powered platform adapted to support stacked coils of strip stock and a guide frame adapted to move toward and away from the periphery of the coil. The strip loops from the coil around the guide frame on the way to the press or other end use. The guide frame is moveable and linked to a rheostat which controls the speed of the driven turntable. The guide frame is biased away from the coil. When the strip coming off the coil slackens, the guided frame moves away from the coil and slows the turntable. When the strip tightens around the guide frame and draws the guide frame closer to the coil, this speeds up the turntable.
Less pertinent, Takahashi, listed above, provides in a first embodiment a powered turntable, with an upright mast extending upward to the side of the turntable, a sleeve extending over the turntable at the top of the mast and a swinging arm at the outer end of the sleeve, the arm having a hook on the end adapted to hang down and to support the offcoming coil. The arm is biased away from the center of the coil and its upper end is mounted on a shaft extending through the sleeve and connected to a variable resistor which sets the speed of the turntable motor. The arm of Takahashi is described as being a "detecting member" or "guide rod" which is supported for movement above and "in a general radial direction from the center of the wound work material toward the outer periphery thereof." The Takahashi arm, in other words, is primarily for detecting the presence of slack in the moving strip and for moving outward from the center of the spool out toward the periphery when it detects such slack to, through the variable resistor, slow down the rotation of the turntable. There is no effort in Takahashi to support the strip in a way that will obviate local stress.